When he wasn’t calling for aid to the jihadi-jammed Syrian rebels this week, Senator Bob Corker was blasting fellow Republican Senator Ted Cruz over the pressure the latter has put on GOP lawmakers to defund Obamacare — pressure, that is to say, to match Republican election-season posturing with real action.

Sen. Bob Corker (R-Tenn.) on Thursday took a whack at Cruz over social media for leading the charge to push Republicans to back only spending bills that defund Obamacare, which many in his own party have predicted will result in a government shutdown blamed on Republicans.

“I didn’t go to Harvard or Princeton, but I can count — the defunding box canyon is a tactic that will fail and weaken our position,” Corker said, a clear reference to the Harvard- and Princeton-educated Cruz.

Corker obviously didn’t need an Ivy League education in order to master the ways of Washington. Just six months ago, he liked Cruz’s “defunding box canyon” so much, he voted in favor it. All Senate Republicans did.